1. Field of the Invention
This invention relates to a method for efficiently separating and recovering useful proteins present in various fluids, and in particular, useful proteins present in very small amounts.
2. Description of the Prior Art
Conventionally, in order to separate and purify proteins by means of a so-called affinity gel carrier, the use of a packed-bed column has been common in laboratory practice and in small-scale industrial production.
However, packed-bed columns have the disadvantage that, when a large volume of fluid is passed through a packed-bed column, as in cases where it is desired to separate and purify very small amounts of physiologically active proteins present in milk, the adsorption efficiency is rapidly reduced owing, for example, to densification of the carrier. In order to keep the adsorption efficiency satisfactorily high, it is necessary to decrease the volume of fluid passed through the column. However, this is disadvantageous from a practical point of view in that the passage time becomes too long to be suitable for the treatment of large volumes of fluid.
There has also been proposed a method for effecting the adsorption by passing a fluid through a fluidized-bed column in a so-called batchwise operation. However, this method involves long-term mechanical agitation and the carrier is very susceptible to damage.
In order to prevent the carrier from being damaged, an attempt has been made to fluidize the carrier by the action of an upflow. However, since this requires a high carrier sedimentation rate, it becomes necessary to enlarge the particle diameter of the carrier or enhance the density of the carrier. Thus, this method had the disadvantage that the type of carrier usable therein is limited.
Meanwhile, a rotary column reactor for activating an immobilized enzyme efficiently has recently been developed (Japanese Patent Publication No. 43228/'81). This reactor consists of a rotary column having an immobilized enzyme placed therein and a housing for enclosing the rotary column, and is intended to achieve efficiently the purpose of activating the immobilized enzyme placed therein and washing it after its use. It is not known whether this reactor can serve to recover very small amounts of useful proteins present in various fluids.